Single space wireless parking with improved antenna placements

ABSTRACT

A wireless parking meter with an improved antenna location is described. The antenna may be located within a covering protruding from the top of the parking meter, allowing radio frequency (RF) signals to be transmitted through a portion of the parking meter with high permittivity to the RF signals. Additionally or alternatively, the antenna may be located within the parking meter housing above a lower parking meter mechanism housing so that RF signals can be transmitted through the dome covering of the parking meter, which may have a high permittivity to the RF signals.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/709,531, filed Dec. 10, 2019, which in turn is a continuation of U.S.patent application Ser. No. 16/165,844, filed Oct. 19, 2018, now U.S.Pat. No. 10,573,953, which in turn is a continuation of U.S. patentapplication Ser. No. 15/348,785, filed Nov. 10, 2016, now U.S. Pat. No.10,141,629, which in turn is a continuation of U.S. patent applicationSer. No. 13/141,977, filed Jun. 23, 2011, now U.S. Pat. No. 9,494,922,which is a national entry application based on PCT Application No.PCT/CA2009/001657 having a filing date of Nov. 18, 2009, and whichclaims priority to U.S. Provisional Patent Application No. 61/140,543,filed Dec. 23, 2008, the contents of which are incorporated herein byreference.

FIELD OF THE INVENTION

The invention relates generally to parking meters, and in particular tosingle space wireless parking meters

BACKGROUND

Often, major cities deploy thousands of single-space parking metersthroughout their jurisdiction. The management of such a deployment islabor intensive. Costs of overhead can be larger than necessary due tothe normal inefficiencies in managing large distributed systems.

Wireless parking meters have been devised that enable the parking meterto communicate with enforcement officers to make parking enforcementmore efficient, as well as to allow for payment using credit cards. Thewireless parking meters may use a protocol such as ZigBee or SSIPCO forthe wireless communication. The wireless systems may have disadvantageswhen used in single space parking meters, which may include, forexample, shorter operating times due to increased power consumption, andcommunication latency due to the communication protocol used.

The wireless single space parking meters may include an antenna fortransmitting radio frequency (RF) signals used for the wirelesscommunication. However, the placement of the antenna has not providedefficient transmission of the RF signals, resulting in higher powerconsumption, lower communication range, or both.

SUMMARY

In one embodiment the current disclosure provides a parking metercomprising a mechanism housing comprising an upper mechanism housingenclosing a display module for displaying parking meter relatedinformation including an amount of parking meter time purchased; and alower mechanism housing enclosing parking meter mechanism components foroperating the parking meter. The parking meter further comprises a radiocommunication module coupled to at least one of the parking metermechanism components for wirelessly communicating parking meterinformation and a parking meter housing enclosing at least the mechanismhousing, the parking meter housing comprising: an upper housingenclosing the upper mechanism housing, the upper housing comprising anopening in the upper housing for viewing at least a portion of thedisplay module; and a lower housing enclosing the lower mechanismhousing. The parking meter further comprises an antenna coupled to theradio communication module located above the mechanism housing totransmit and receive radio frequency (RF) signals through at least aportion of the parking meter that has a high emissivity to RF signals(the transmission path).

In another embodiment the current disclosure provides a parking metercomprising a mechanism housing comprising an upper mechanism housingenclosing a display module for displaying parking meter relatedinformation including an amount of parking meter time purchased; and alower mechanism housing enclosing parking meter mechanism components foroperating the parking meter. The parking meter further comprises a radiocommunication module coupled to at least one of the parking metermechanism components for wirelessly communicating parking meterinformation and a parking meter housing enclosing at least the mechanismhousing, the parking meter housing comprising: an upper housingenclosing the upper mechanism housing, the upper housing comprising anopening in the upper housing for viewing at least a portion of thedisplay module; and a lower housing enclosing the lower mechanismhousing. The parking meter further comprises an antenna coupled to theradio communication module located above the mechanism housing totransmit and receive radio frequency (RF) signals, the antenna having ashape selected from the group consisting of a ‘T’ shape; an ‘F’ shape;and an ‘L’ shape.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the novel technology are described herein, with referenceto the drawings in which,

FIG. 1A depicts a schematic of a typical single space parking meter;

FIG. 1B depicts an exploded view of the single space parking meter ofFIG. 1A;

FIG. 2A depicts a schematic of an embodiment of a single space parkingmeter with an improved antenna placement;

FIG. 2B depicts an exploded view of the single space parking meter ofFIG. 2A;

FIGS. 3A-3D depict various views of an illustrative upper housing of anillustrative parking meter;

FIG. 4A-4C depict various views of an illustrative dome covering of anillustrative parking meter;

FIG. 5A-5C depict schematics of various embodiments of an illustrativeparking meter with improved antenna placement; and

FIGS. 6A-6D depict schematics of illustrative antenna configurations;

FIGS. 7A-7E depict results of radiation pattern simulations of amonopole antenna;

FIGS. 8A-8E depict results of radiation pattern simulations of a Tantenna;

FIGS. 9A-9E depict results of radiation pattern simulations of an Lantenna;

FIGS. 10A-10E depict results of radiation pattern simulations of an Fantenna;

FIGS. 11A-11C depict schematics of an alternative antenna arrangement ofan illustrative parking meter with improved antenna placement.

DETAILED DESCRIPTION

A wireless parking meter is described herein that provides for betterplacement of an antenna. The location of the antenna described hereinallows the antenna to transmit and receive radio frequency (RF) signalsthrough a portion of the parking meter that has a high permittivity tothe RF signals. Advantageously, the location of the antenna describedherein allows for a more power efficient wireless parking meter, alarger communication range, or both. Furthermore, current parking metersmay be modified to make use of the improved antenna locations describedherein, reducing the cost of implementing wireless parking meters.

FIGS. 1A and 1B depict a typical single space parking meter 100. Asingle space parking meter 100 typically comprises an outer housing 102,or simply a housing, comprising multiple components. The housing 102typically comprises a two-part upper housing comprising of a removableupper housing cap 104 that is typically locked or otherwise secured to ameter housing 110 which in turn is attached to a lower vault housing112. The upper housing cap 104 generally has a semi elliptical shapewith an opening in the upper housing cap for viewing a display of theparking meter 100. It will be appreciated that the shape of the upperhousing cap may be of other shapes. The upper housing cap 104 mayinclude an opening on both sides in order to allow viewing of thedisplay from either side of the parking meter 100. The opening in theupper housing cap is sealed by a dome situated within the housing. Thedome is typically made from a high strength transparent material, suchas Lexan. The meter housing 110 may include space for holding a coinvault, or alternatively may have a further lower vault housing 112 thatcan be secured to the meter housing 110 to hold the coin vault. Theouter housing 102 provides physical protection for the components of theparking meter. The outer housing 102 also protects the components of theparking meter from the exterior environment. The outer housing 102 istypically made from a high strength metal that provides sufficientprotection against intentional vandalism.

The outer housing 102 encloses a parking meter mechanism housing andvarious parking meter mechanism components. The parking meter mechanismhousing and parking meter mechanism components may be referred tocollectively as the parking meter mechanism 105. The parking metermechanism 105 provides for the various functionality of the wirelessparking meter 100. For example, the mechanism components may include acoin chute 114 for detecting coins inserted into the parking meter 100,a card reader 116 for detecting magnetic stripe, or smart-chip cardsinserted into the parking meter 100, a main processing board (not shown)including a processor and memory storing instructions that, whenexecuted by the processor, control the operation of the parking meter100 as well as a display 118, or display module, for displaying parkingmeter information, such as an amount of parking time purchased, parkingmeter error messages, expired time, etc.

The parking meter mechanism housing generally comprises two sections, anupper mechanism housing 106 that houses the display 118 and a lowermechanism housing 108 that houses the parking meter mechanismcomponents. It will be appreciated that while the display 118 is acomponent of the parking meter, it is not referred to herein as amechanism component as it is housed above the mechanism components, suchas the coin chute 114, card reader 116 and main processing board.Furthermore, while the upper mechanism housing 106 is located above thelower mechanism housing 108 it will be appreciated that this refers tothe assembled mechanism 105. That is, the mechanism housing may beassembled from a back frame that includes a portion of the uppermechanism housing and the lower mechanism housing. The mechanismcomponents and the display 118 may be attached to the back frame. Afront frame may be secured over the mechanism components to provide thelower mechanism housing 108 of the assembled mechanism housing.

The parking meter outer housing 102, and the parking meter mechanismhousing, present a problem when transmitting and receiving RF signals.The materials of the parking meter outer housing 102 and the mechanismhousing are opaque to RF signals, or at least attenuate the transmittedRF signals. As a result the RF signals need to be transmitted with ahigher power, consuming more power from a battery powering the parkingmeter 100. Alternatively, the same power may be used to transmit the RFsignal; however, this will result in a reduced communication range andpossibly require additional infrastructure to provide the wirelesscommunication with the parking meter 100.

In order to increase the transmission efficiency of the RF signals fromthe parking meter 100, improved locations for the placement of theantenna are described herein. The improved wireless parking meterprovides an antenna within the parking meter housing that locates theantenna such that the antenna can transmit and receive RF signalsthrough a portion of the parking meter housing that has a highpermittivity to RF signals. To further increase the transmissionefficiency, improved shapes of antennas are described.

FIGS. 2A and 2B depict an illustrative embodiment of an antennaplacement for a wireless parking meter 200. FIGS. 2A and 26 do notdepict the lower vault housing or the meter housing of the wirelessparking meter. The wireless parking meter 200 includes a fin cover 216that protrudes through a second opening in the upper housing cap 202.The fin cover 216 encloses the antenna 210. The fin cover 216 isconstructed from a material with a high permittivity to RF signals. Theprotruding fin cover 216 allows the antenna 210 to be located above theupper housing cap 202. As depicted in FIG. 2B the fin cover 216 mayhouse the antenna 210 which is located on a radio board 206. The radioboard 206 may include a radio control module 208 for controlling thetransmission, and reception, of the RF signals. The radio control module208 may be coupled to a parking meter mechanism component housed in thelower mechanism housing 108, such as the main control board, via anappropriate cable 212 with an appropriate connector 214. It will beappreciated that while the radio control module 208 is depicted as beinglocated on the radio board 206, it may be located within the parkingmeter mechanism housing, or other convenient locations. If the radiocontrol module 208 is not located on the radio board, the cable 212 andconnector 214 may be used to connect the antenna to the radio controlmodule 208. Additionally, it will be appreciated that, while the radiocontrol module 208 has been described as being a separate component, itmay be included as a component of the main control board or otherparking meter mechanism components.

As described above, the fin cover 216 protrudes upwardly through asecond opening in the upper housing cap 202. The second opening, or finopening, is sized to allow a portion of the fin cover 216 to passthrough. However a base portion 217 of the fin cover is enlarged so thatit does not pass through the fin opening of the upper housing cap 202.This base portion 217 of the fin cover may also seal the fin opening inthe upper housing. It will be appreciated that other means of securingthe fin cover 216 to the upper housing cap 202 are possible, and will beapparent to those skilled in the art.

The fin cover 216 allows the antenna 210 to be located above the upperhousing cap 202 of the parking meter 200. The fin cover 216 isconstructed from a material with a higher permittivity to RF signalsthan the housings of the parking meter. As such, the fin cover 216provides an improved antenna placement in which the antenna 210 cantransmit and receive RF signals through a portion of the parking meter200 that has a high permittivity to RF signals.

FIGS. 3A-3D depict various views of an illustrative embodiment of anupper housing for a parking meter 200. The upper housing cap 202 may bemodified from an upper housing cap as used in previous parking meterhousings. The upper housing cap 202 includes first openings 306, whichmay be referred to as dome openings. The dome openings 306 provide anopening through which the parking meter display may be viewed. If thedisplay of the parking meter 200 is a dual sided display, dome openings306 may be provided on each side of the upper housing cap 202. The upperhousing cap 202 includes a central portion 308 located between the twodome openings; or alternatively located about a center of the upperhousing cap 202 if only a single dome opening 306 is provided. Thecentral portion 308 of the parking meter housing cap generally has asemi elliptical, or an actuate, shape. A second opening, or fin opening310, is provided in the upper housing cap 202. As depicted in theFigures, the fin opening 310 is located centrally in the central portion308 of the upper housing cap 202. It will be appreciated that the finopening 310 is located centrally within the central portion 308 of theupper housing cap 202 for aesthetic reasons, and for the simplicity offorming the opening within the central portion 308. The fin opening 310may be located at any suitable location of the upper housing cap 202that allows the fin cover 216, and so the antenna housed within, toprotrude away from the upper housing cap 202. Additionally, although thefin opening 310 has been described as being positioned within the upperhousing cap 202, it is possible to locate the fin opening 310, and thefin cover 216, within any portion of the parking meter outer housing,for example within the meter housing. It will be appreciated thatpositioning the fin opening 310 within the upper housing cap 202 has theadvantage of being relatively easy to replace if required. If the finopening 310 is located within the meter housing, the upper housing cap202 would be required to be removed, as well as possibly the parkingmeter mechanism housing in order to replace or service the fin cover 216located within the fin opening 310. Removing the parking meter mechanismhousing may require further disassembly of the parking meter 200 thanwould be required if simply placing the fin opening 310 in the upperhousing cap 202.

FIGS. 4A-4C depict various views of an illustrative dome cover 404. Thedome cover 404 may be used with the upper housing cap 202 of FIGS.3A-3D. The dome cover 404 includes a radio board opening 406 that islocated to correspond with the fin opening 310 of the upper housing cap202 of FIGS. 3A-3D. The radio board opening 406 of the dome cover 404allows the radio board 206 to be situated above the dome cover 404 whilehaving a portion of the radio board 206 pass through the dome cover 404.The radio board opening 406 may register the radio board 206 within theparking meter housing in order to securely position the radio board 206within the fin cover. The size of the radio board opening 406 may vary.The radio board opening 406 may be sized to accommodate the radiocontrol module 208 located on the radio board 206. Alternatively, theradio board opening 406 may be sized to accommodate only the boardportion of the radio board 206, while the radio control module 208, ifpresent, is situated above or below the dome cover 404. Alternatively,the dome cover 404 may not have a radio board opening 406 at all, andthe radio board 206 may be wholly located above the dome cover 404.

If the dome cover 404 includes a radio board opening 406, it may be usedto route the connection cable 212 from the radio board 206 to theappropriate location of the parking meter mechanism. If the radio boardopening 406 is not present, the cable 212 may be routed along the domecover 404 to a position where the dome cover 404 meets the parking meterhousing and then routed to the appropriate connection location on theparking meter mechanism.

FIGS. 5A-5C depict various arrangements of the radio board 206 and fincover 216 within the upper housing cap 202 and dome cover 404. FIG. 5Adepicts a dome cover 404 that does not include a radio board opening.The radio board 206, which may include a radio control module 208, iswholly located above the dome cover 404. The fin cover 216 is locatedbetween the dome cover 404 and the upper housing cap 202. A main portionof the fin cover 216 protrudes through the fin opening in the upperhousing cap 202. A base portion of the fin cover 216 extends past thefin opening in the upper housing cap 202 and captures the fin cover 216between the dome cover 404 and the upper housing cap 202, helping toensure that the fin cover 216 is not easily removed through the finopening of the upper housing cap 202.

FIG. 5B depicts an alternative embodiment of the arrangement of theradio board 206 and fin cover 216 within the upper housing cap 202 anddome cover 404. The dome cover 404 of FIG. 5B includes a radio boardopening 502 that is sized to allow the radio board 206 to pass throughbut not a radio control module 208, if present. The fin cover 216 islocated between the dome cover 404 and the upper housing cap 202 in asimilar manner as in the embodiment of FIG. 5A. If the radio controlmodule 208 is present on the radio board 206, it may be located above orbelow the dome cover 404. If it is located above the dome cover 404, abottom surface of the radio control module 208 may rest on an uppersurface of the dome cover 404, and position the radio board 206 withinthe fin cover 216. If the radio control module 208 is positioned belowthe dome cover 404, it may be held between the upper mechanism housing(not shown) and the dome cover 404.

FIG. 5C depicts a further alternative embodiment of the arrangement ofthe radio board 206 and fin cover 216 within the upper housing cap 202and dome cover 404. The radio board opening 502 in the dome cover 404 isexpanded to allow the main portion of the fin cover 216 to pass through.The base portion of the fin cover 216 is captured by the dome cover 404,preventing the fin cover 216 from passing through the radio boardopening 502. The fin cover 216 and the radio board 206, is held inposition between the upper mechanism housing and the dome cover 404.

The radio board 206 may be further held in position within the fin cover216, of any of the described embodiments, by a radio board clip or othersuitable means. Although not required to locate the radio board 206within the fin cover 216, the radio board clip may hold the radio board206 within the fin cover 216, which may facilitate assembly ordisassembly of the parking meter.

As is apparent from the above description of various embodiments, theantenna 210, and possibly the radio control module 208, is housed at thetop of the parking meter within the fin cover 216. The fin cover 216provides the required physical strength to prevent, or reduce, thelikelihood that the antenna 210 can be broken off from the parkingmeter.

The fin cover 216 is constructed from a material with a highpermittivity to RF signals and in particular to the RF signals used bythe radio control module 208 of the parking meter. The fin cover 216 maybe made from a plastic or similar material. The following table providesa listing of possible suitable materials for the fin cover 216, as wellas their RF characteristics.

TABLE 1 Table showing RF properties of various materials DielectricConstant (Dk) Loss Tangent (Df) (Relative Permittivity) (DissipationFactor) Product & Grade Color 1.2 GHz 2.4 GHz 10 GHz 1.2 GHz 2.4 GHz 10GHz HB Rated CYCOLOY ® C1000HF natural 2.72 2.71 0.0045 0.0045 CYCOLOY ®C1200HF natural 2.72 2.75 0.0046 0.0046 GELOY ® CR7520 unknown 2.98 2.972.87 0.0212 0.0186 0.0148 LEXAN ® 121R natural 2.76 2.80 0.0047 0.0047LEXAN ® EXL1414 unknown 2.83 2.86 0.0062 0.0056 LEXAN ® EXL1414 (dry)unknown 2.81 2.85 0.0060 0.0052 XENOY ® 5731 unknown 2.88 2.93 2.850.0082 0.0069 0.0057 ® X7110 natural 2.83 0.0121 XYLEX ® X8210 NA9A0042.84 0.0141 V-2 Rated XYLEX ® X7200 NA9A008 2.87 0.0134 V-1 RatedNORYL ® EN265 unknown 2.71 2.69 2.65 0.0029 0.0030 0.0029 V-0 RatedULTEM ® 1000 unknown 3.05 3.09 3.05 0.0025 0.0031 0.0047 CYCOLOY ® C6200Natural 2.87 0.0134 V-0 Rated, UV Stabilized LEXAN ® 923A unknown 2.812.82 2.76 0.0058 0.0052 0.0050 VALOX ® 357U unknown 2.92 2.91 2.860.0122 0.0103 0.0084 VALOX ® 364 unknown 2.88 2.93 2.85 0.0079 0.00740.0061

The fin cover 216 may house the radio control module 208 and the antenna210. The antenna 210 may be formed on the radio board 206. Although thearrangement of the antenna 210 within the parking meter 200 as describedabove allows RF signals to be transmitted, and received, through aportion of the parking meter 200 with a high permittivity to RF signalsand so provides a more efficient wireless parking meter 200, furtherefficiency may be gained by the type, or shape, of antenna 210 used.

FIGS. 6A-6D depict various shapes of antennas 210A-D that can be usedwithin wireless parking meters. The antennas 210A-D may be formed on theradio board by a metal trace or other techniques known to one skilled inthe art. FIGS. 6A-6D also depict the characteristics of connection tothe antennas 210A-D that may provide improved impedance matching betweenthe antenna and the RF signal source. It will be appreciated that thecharacteristics of the connection, including components connected to theantenna and their values may vary depending upon the specificcharacteristics of the antenna used. One skilled in the art willappreciate that the values of components may be readily determinedthrough experimentation, simulation, or through theoreticalcalculations.

FIG. 6A depicts a monopole antenna 210A. The monopole antenna 210A iscoupled to the source through an inductor with a value of 29 nH. A 7.5pF capacitor is connected in parallel with the source. FIG. 6B depicts aT antenna 210B. A base of the T is coupled to the RF source through a10.5 nH inductor. A 6.0 pF capacitor is connected in parallel with thesource. FIG. 6C depicts an L antenna 210C. A short leg of the antenna210C is connected to the source with a 4.7 pF capacitor connected inparallel. FIG. 6D depicts an F antenna 210D. A short arm of the F iscoupled to the source. No additional capacitors or inductors arerequired for impedance matching in the arrangement of FIG. 6D. Variousspecific antenna arrangements have been described with reference toFIGS. 6A-6D. It will be appreciated that these antenna shapes are merelyillustrative, and other antennas may be used in a wireless parking meterin accordance with the present disclosure.

FIGS. 7A-7E depict characteristics of the monopole antenna 210A of FIG.6A. The characteristics were determined through a simulation of theantenna located above the upper housing of a parking meter housing. FIG.7A depicts the impedance matching characteristics of the monopoleantenna 210A. FIGS. 7B-7E depict the transmission characteristics of thesimulated monopole antenna 210A along different planes.

FIGS. 8A-8E depict characteristics of the T antenna 210B of FIG. 6B. Thecharacteristics were determined through a simulation of the antennalocated above the upper housing of a parking meter housing. FIG. 8Adepicts the impedance matching characteristics of the T antenna 210B.FIGS. 8B-8E depict the transmission characteristics of the simulatedantenna along different planes.

FIGS. 9A-9E depict characteristics of the L antenna 210C of FIG. 6C. Thecharacteristics were determined through a simulation of the antennalocated above the upper housing of a parking meter housing. FIG. 9Adepicts the impedance matching characteristics of the L antenna 210C.FIGS. 9B-9E depict the transmission characteristics of the simulatedantenna along different planes.

FIGS. 10A-10E depict characteristics of the F antenna 210D of FIG. 6D.The characteristics were determined through a simulation of the antennalocated above the upper housing of a parking meter housing. FIG. 10Adepicts the impedance matching characteristics of the F antenna 210D.FIGS. 10B-10E depict the transmission characteristics of the simulatedantenna along different planes.

An improved location for an antenna of a wireless parking meter has beendescribed above. The antenna is located above the upper housing of theparking meter housing within a fin cover that is constructed from amaterial with high permittivity to the RF signals used by the wirelessparking meter. Although the fin cover provides for the desirableplacement of the antenna above the upper housing of the parking meter,the antenna may be located in other positions. For example, as describedabove, the fin cover may be located on a portion of the parking meterhousing. Furthermore, as described below, the antenna may also belocated within the housing of the parking meter.

FIGS. 11A-11C depict various views of an alternative embodiment of awireless parking meter 1100. As seen in FIG. 11C, an antenna 1102 can belocated within the housing 1104, above the lower mechanism housing 1106.The antenna 1102 is positioned within the opening of the upper housing1108. A dome cover, such as dome cover 404, provides a transmissionpath, which has a high permittivity to RF signals. The upper housing1108 may include a radio board holder 1110 for securing the radio board1112, which may include the radio control module. The antenna 1102 maybe positioned in front of the display as depicted, or may be located toone side of the display.

Unlike the antennas described above with reference to FIGS. 6A-D, whichare formed on the radio board, the antenna 1102 is made from a selfsupporting wire that allows the antenna 1102 to be positioned verticallywithin the dome opening in the upper housing 1108, above the lowermechanism housing 1106. The self supported wire allows the antenna 1102to be positioned in front of the display without blocking, orinterfering with, the visibility of the display. The self supportedantenna 1102 may be formed into various shapes. A T antenna is depictedin FIG. 11C.

Although the fin cover locates the antenna above the upper housing, itmay require that the upper housing be modified to include a fin coveropening to allow the fin cover to protrude from the upper housing. Whilethe self supported antenna may be positioned within the housing, and soavoid modification of the upper housing, it may not have as advantageoustransmission characteristics as the fin cover placement. The display andthe upper mechanical housing may provide a transmission path on one sideof the antenna with low permittivity to the RF signals. Although oneside of the antenna may be blocked by the relatively low permittivity ofthe display and upper mechanism housing, the transmission path from theother side of the antenna will advantageously pass through the openingin the upper housing through the dome cover. The dome cover is made froma transparent material with high permittivity to the RF signals.

As described herein, locating the antenna of the wireless parking meterso that the RF signals will have a transmission path that passes atleast partly through a portion of the parking meter with highpermittivity to RF signals, allows for more efficient transmission of RFsignals. The more efficient transmission of RF signals from the wirelessparking meter may provide either a more power efficient wireless parkingmeter, a wireless parking meter with extended communication range, orboth.

Furthermore, the transmission efficiency can also be improved byimproving the shape of the antenna. As described herein, a ‘T’ shapedantenna has superior transmission characteristics than previous antennasused in wireless parking meters. Although, the ‘T’ shape provides thebest transmission characteristics according to the simulations andcalculations performed, the ‘L’ shaped and ‘F’ shaped antennas alsoprovided superior transmission characteristics for use in a wirelessparking meter over a typical monopole antenna.

The embodiments described above are intended to be illustrative only.The scope of the invention is therefore intended to be limited solely bythe scope of the appended claims.

What is claimed is:
 1. A parking meter comprising: parking metermechanism components adapted to be powered by at least a battery, theparking meter mechanism components comprising: at least one paymentcomponent for accepting payment; a display for displaying parking meterrelated information; and an antenna for transmitting and receiving RadioFrequency (RF) signals; an exterior housing at least partially enclosingthe parking meter mechanism components, the exterior housing providingprotection to the enclosed parking meter mechanism components from anexterior environment; and a transmission path made from a materialproviding low attenuation of the RF signals transmitted from theantenna.
 2. The parking meter of claim 1, wherein the material oftransmission path is selected from the group consisting of: LEXAN;CYCOLOY; GELOY; XENOY; XYLEX; NORYL; ULTEM; and VALOX.
 3. The parkingmeter of claim 1, further comprising an antenna cover, wherein thetransmission path is part of the antenna cover.
 4. The parking meter ofclaim 3, wherein the antenna cover is a separate component from theexterior housing and secured to the exterior housing.
 5. The parkingmeter of claim 1, wherein the exterior housing comprises a first portionsecured at a parking meter location and a second portion securable tothe first portion.
 6. The parking meter of claim 5, wherein the firstportion comprises a lower vault housing and a lower meter housing. 7.The parking meter of claim 1, wherein the parking meter mechanismcomponents are secured to a frame providing a removable mechanismcomponent that can be removed from the exterior housing as a singlecomponent.
 8. The parking meter of claim 1, wherein the transmissionpath is formed as part of a fin cover that extends away from theexterior housing.
 9. The parking meter of claim 1, wherein the antennais part of a radio board.
 10. The parking meter of claim 9, wherein theradio board is located within a removable cover that includes thetransmission path.